Zusammenfassung der Ressource
Biology B1 Revision
- Diet and drugs
- Need a balanced diet for energy
- Out of balance diet results in
malnourishment (not starvation!)
- Can result in obesity (causing
arthritis, type 2 diabetes, high
blood pressure, heart disease,
cancer)
- Lack of food can result in
slow growth, fatigue, no
resistance to infection,
irregular periods, scurvy
- Need exercise to burn energy
- Health can be affected by inherited
factors-underactive thyroid gland
- Metabolism rate of chemical reactions in the body
- Drugs change body chemistry
- Medicinal
- Anitbiotics
- Penicillin
- Morphine
- Testing medicines
- 1. Drugs are tested on tissues
- 2. Drug on mammals
- 3.Test on healthy volunteers
- 4. Testing on people with the illness- finding optimum dosage
- 5. Placebo tests
- Thalidomide
- Performance enhancing
- Anabolic steroids and stimulants
- All banned by sporting bodies
- Recreational
- Enjoyment, relaxation
- Legal or illegal
- Tobacco, alcohol, cannabis
- Fighting disease
- 2 main types of
pathogens- Bacteria
and viruses
- Bacteria- very small living cells
- They either damage your cells
or produce toxins (poisons)
- Viruses are not cells
- They invade your cells, make
copies of themselves, then the
cell bursts releasing the viruses
- Drugs and vaccinations
- Vaccinations are a weak or
inactive form of the virus that
carry antigens, making your
body produce antibodies
- Pros: Helped control lots of
infectious diseases, and epidemics
can be controlled and be less likely
tobreakout
- Cons: They don't always work
and sometimes trigger bad
reactions, even though these are
rare
- A lot of drugs only reduce the
symptoms of the disease, but
don't actually cure it.
- However antibiotics such as
penicillin, prevent or kill the bacteria
inside your blood
- Antibiotics do not destroy
viruses, as it would kill
your body's cells
- Bacteria can become resistant to antibiotics, which is why you should
always complete a course of antibiotics, but do not take too much or too little
as it increases the bacteria's rate of mutation or reproducution
- 1st line of defence
- Skin, hairs, tonsils,
- 2nd line of defence
- Mucus, tears, non-specific
- 3rd line of defence
- Antibodies, all specific, acquired with exposure to pathogens
- Producing antibodies:
- 1. White blood cells engulf the pathogen
- 2. The white blood cells produce
proteins called antibodies to lock onto
and kill the invading cells.
- 3. Antitoxins are produced which
counteract toxins produced by the
invading bacteria
- Hormones and the nervous system
- Sense organs detect stimuli
using different receptors
- Reflex actions
- Stimulation of the pain receptor
- The impulse travels along the relay neurone
- Then along the motor neurone
- Finally it moves to the effector
- (Spinal cord)
- The Menstrual Cycle
- Day 1-4= Uterus lining breaks down
- Day 4-14= Lining for the uterus builds up
and egg is released (Day 14)
- Day 14-28= Lining is maintained
- Cycle starts again
- Hormones
- FSH-Is produceD by the pituitary gland,
Causes egg maturation, Stimulates
ovaries to produce oestrogen
- Oestrogen- Is produced by the
ovaries, Causes pituitary to produce
LH, Inhibits further release of FSH
- LH- Produced by the pituitary gland,
Stimulate the release of an egg
during the cycle
- Hormones are chemical messengers
- Fertility
- Oestrogen prevents the release of an egg, controlling fertility
- FSH and LH help women to get pregnant
- IVF- In-vitro fertilisation
- Plants
- Auxins
- Auxins are produced in the tip of the stem
- Sunlight breaks down the side of auxins
- Causing the roots or stems to bed
towards sun or water
- Tropisms
- Phototropism- Light
- Geotropism- gravity
- Hydrotropism- water
- Thigmotropism- touch
- Homeostasis
- Constant internal environment
- Iron content is regulated by kidneys
- Temperature is controlled by the brain- 37 degrees
- Sugar and water are also controlled by the body
- Adaptations, Environmental change and Evolution
- Adaptations
- Large surface area
compared to volume-
losing more body loss
- Good efficiency
with water
- Camoflage
- Teeth, claws,
poisons, warning
colours
- Organisms compete for resources to survive- light
water space shelter mates nutrients food
- Environmental change biotic (living)
and abiotic (non-living) factors
- Living- diseases,
predators, prey,
competitors
- Measured using living indicators-
Lichen, sewage-bacteria
- Satellites, weather stations,
rain gauges, oxygen metres
- Non-living- Temperature,
Rainfall, air or water pollution
- Affects population numbers and distribution
- Energy transfer and decay
- All energy on earth is
from the sun
- Algae and animals that respire
- Waste products and decay put elements back in the air
- Variation occurs as a result of sexual reproduction
- Evolution
- Darwin
- Natural Selection
- Variation
- Evolution can occur due to mutations
- Had evidence
- Lemark
- Fountain of Life
- "Use it or Lose it"
- Did not have evidence
- Genes and DNA
- Most cells have a nucleus
- In this, humans have 23 pairs of chromosomes
- Chromosomes have genes, which control the development of different characteristics
- A gene is a short length of the chromosome which is quite a long length of DNA
- Reproduction
- Sexual reproduction produces
genetically different cells
- Asexual reproduction produces
genetically different cells
- Cloning
- Plants can be cloned from cutting
- Animal clones use embryo transplants
(artificially fertilise sperm and eggs)
- Adult Cell cloning (using a body cell nucleus)
- Reduced gene pool, no variation,
preserve endangered species
- No immunity to disease
- Genetic
engineering- cut
and paste genes
- Pyramids of...
- Numbers
- Not always
a pyramid
- The amount of
animals at each stage
- Biomass
- Always a pyramid
- Very few exceptions
- Bottom level is always a producer
- Biomass- Mass of
living material (dried)
- The amount of energy
at each stage
- Trophic level-
feeding level